The western portal of the Kittatinny Mountain Tunnel.
The Kittatinny Mountain Tunnel is a tunnel through Kittatinny Mountain in Franklin County, Pennsylvania. It is one of seven tunnels completed for the Pennsylvania Turnpike, and one of four still in use today. The Kittatinny Mountain Tunnel is 4,727 feet (1,441 m) in length, and is located 600 feet (180 m) west of the Blue Mountain Tunnel, separated by the Gunter Valley. 
The Kittatinny Mountain Tunnel's western portal is featured on the first postcard during the opening sequence of National Lampoon's Vacation.